Hammer meg



H. N. PACKARD.

FLUID METER. APPLlCATION mm FEB. 9. 191a.

' Patented Nov. '11, 1919.

M aw

"UNITED STATES PATENT OFFICE.

HORACE CONSIN.

N. PACKARD, OF MILWAUKEE, WISCONSIN, ASSIGNOE TO THE CUTLER- HAMMER MFG. 00., OF MILWAUKEE, WISCONSIN,

a CORIOBAIION or WIS- 'FLUIDMETEB.

Patented Nov. 11,1919.

Application filed February 9, 1918. Serial No. 216,226.

To all whom it may concern Be it known that I, HORACE N. PACKARD, a citizen of the United States, residing at Mil: waukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Fluid-Meters, of which the following is a specification.

T his invention relates to fluid meters.

It relates particularly to meters for measuring the rate of flow of fluids, by imparting heat thereto and determining either the effect of the imparted heat on the fluid or the cooling effect of the fluid on the heater.

Meters of this type generally have an electric heater to impart heat to the fluid, and one or more electric resistance thermometers to measure the temperature thereof.

The location of the resistance thermometer 0r thermometers, relative to the heater, is

usually such that the thermometers are affected by the radiant energy from the heater.

This radiant energy may affect the temperature of the thermometer without correspondingly affecting the temperature of the transparent medium of gas or other fluid through which the rays ass. Errors may thus be introduced in t e reading'of the meter.

In the patent to John C. Wilson, No.

1,257,568, of Feb. 26, 1918, means are shown for preventing errors in the reading of the meter due to the effects of the energy that radiates from the heater. This means, in the embodiment shown in said patent, comprises a ray screen located between the heater and each thermometer resistance to obstruct and absorb the rays from the heater, and to im part the absorbed heat to the fluid. The screens are so constructed that they will obstruct and absorb substantially "all of the heat rays without materially obstructing-the flow of the fluid.

It has been found in practice that the therbe affected by radiant energy from other sources heater. For instance,the walls of the conduit may, under certain conditions, be hotter 0r colder-than the fluid. Heat energy may therefore be radiated from the walls of the conduit at a point beyond the thermometer re is an an he r ys may be d ct d onpass .the temperature the like, from the gas. 7

than. the

.The heat energy wi purpose for which it is intended. If all the rays were absorbed withoutdirectly strik the unprotected side of the thermometer reslstance. According to this invention, the means for obstructing and absorbing the heat rays serves to absorb the heat rays coming from either direction, and therefore serves to protect both s1des of'the thermometer resistance. Under these conditions the thermometer resistance. will be protected from the heat rays that are radiated from any source, whether the source be the electric l heater or the walls of the conduit.

The object of this invention is to provide a meter in which errors, due to the effects of radiant energy from any source whatsoever, will be prevented.

Before describing the meter, the action of radiant energy will be briefly explained.

I Radlant energy is transmitted in all directions from a source of heat. These rays may through a medium such as a gaswithout producing any apparent effect on the gas. .If the surface of the'thermometer resistance, or-other object in the path ofthc rays, is a perfert reflecting surface, all of the rays will be reflected, and none will be absorbed. Under these conditions the temperature of. the thermometer will not'be affected. If, on the other hand, the surface of the thermometer resistance is a perfect absorbing surface, the rays will be absorbed and none will be reflected. In the latter case,

of the thermometer resistance will be raised. Under practical conditions the surface of the thermometer resistance is neither a perfect reflecting nor a perfect absorbing surface. Furthermore, the ray'absorbing and reflecting properties of the thermometer resistance may change, due to the deposits of tar, naphthalene, and

. If the rays strikesome obstructing surface I between the heater and the thermometer resistance, a substantial energy will be absorbed and transmitted to the gas to raise the temperature thereof.

1 then be used for the ing the thermometer resistance, and the absorbed heat dissipated to. the fluid or gas, an ide l QQBQll iQH would be obtained.

portion of theheat aforesaid application for absorbing-the rays from the heater before they reach the ther- I The accompanying 'r'ay' screens shown in Fig. 2-for absorbing" axs'therdygw .7 a

' "thermometer resistance are mometer resistance. "The meter herein described has 'means for absorbing the rays not only from theheater, but also fromother sources adjacent to the thermometer resistance. This means then transmits jtheheat energy to the as. I s

The meter erein shown is ofgthe type commonly 'known as a Thomas meter.

,by 'theelfectof'the heat transfer'on the fluid,

' or theeffect of the heat transfer on the heater,

I of the'heater. H In practice,- theheater and ripril10, 1917,{ so that the thermometer reautomaticallyyary the current supplied to points where. the thermometer resistances v the fluid. The'mechanism connectedlwithjthe heater and thernismhasfirotbeen shown. 7 r drawmg V lllustrates, in

a somewhat diagra of ray. absorbing means associate with t c Fig. 3,is -a:frontelevation of one of the 1' l Fig. lis averticalsection of the ray screen "taken'online 4+4 of'Fig.r3.

l O ielthat theiportionfof the meter shown in 7 j Figs. '1 and 2 comprises a housing 1- which f 'FOIfthGf present purpose, it is sufficient to isadapted tobe connected in the gas main 'fljAt'theientra-nceside of'the heater 2 is a thermometer resistance 3,

and at the exit is a. similar ther .sidebf the heater 2 there mometer, resistance 4t. All

A. Ineterof this type may comprise an electric heater for imparting heat to the flu d, ands 1 oneor more thermometer reslstances whereheater 2 and each connected with 3 f automatic mechanism'of the type shown 1n jthe patentto C. C. Thomas, No. 1222,4592, of r 7 I sistances will act thr g a galmnomepai' 'will be noted that the constitutes a separate unit which may be inmmatic way, only the s housing of the meter, and the heater and "1 j thermometer resistanceslocated therein] I l {.Inthe drawing Figure 1 is a vertical sec- 7 I tionofjthe metenhousing showingonety e thermometer reslstances. v f' i 2 is a vertical section ofa meter showing a different type of ray absorbingmeans o 1 associated withthe thermometer resistances."

long narrow passages which of the resistances are connected by means of suitable leads 5 to a panel board 6 located in the terminal hor'lsing 7. Proper electrical connectlons may be made between the terminal board 6 and the other mechanism of the meter (not shown) by the conductors 8.

The thermometer resistance 4 is mounted in a tubular frame 9. The heater 2 and thermometer resistance 3 are mounted in similar tubular frames 10 and 11 respectively. These tubular frames, together with the end'frames 12 and 13, go to make up a passage or conduit through which the fluid to be measured flows. l

A ray screen 14 is These ray screens are constructed in the in the aforesaid patent to John G. Wilson.

v So far as the present invention is concerned their specific construction is nnmaterlal.

Oneitype of screen disclosed in the lVils-on patent is'shown in Figs. 3 and 4. It comprises aplurality of concentric circular strips .of metal 15. These circularstrips of metal may be held in position by any suitable means,"such as the cross rods In the meter shown in Fig. 1 the circular strips 15 are associated directly with the tubular frame that. carries the thermometer resistance, whereasin Fig. 2 the circular strips 15 are mounted in separate tubular frames 17. It is this type of my screen that v is shown in detail in Figs. 3 and 4. By constructing the ray screen in this manner it entire screen structure serted between thetubular frame carrying the thermometer resistance and the tubular frame carrying the heater resistance.

' The structure so far described is substantially the same as that'in the aforesaid \Vilson patent,'and the screens serve to obstruct and absorb the rays in the manner described in said patent. In order that thefunction of the screens may be clearly understood, the manner in'which thescreens intercept and absorb the'rays will be herein briefly repeated. I a v The concentric strips .15 form relatively do. not. materially interfere with, or obstruct, the flow of the fluid. Nearly all the heat rays which pass at anangletothedirction of flow of the fluid will'strike one of the circular yforebe obstructedand absorbed. However,

,gthrough which flows the 'fluidfto bemeas-- ured. V Positioned in the-housing is an elec- T tric heater 2 forimparting heat to the fluid.

the screens do not obstruct the rays which lie substantially parallel with the direction of the'flow of the fluid, but any errors which may be produced by not absorbing these comparatively few rays is negligible. The

reater part of the rays emanating from the lie/ lter will strike and be absorbed by one of or bolts 16. v

positioned between the SO thermometer reslstancer w same results. For instance,a modification the strips of one of the ray screens, and

shown in the aforesaid IVilson patent com- 7 prises strips of metal passing across the conduit transversely in two directions so as to provide a large number of rectangular tubular openings or passages. The strips of metal or other material forming these passages, perform the same function of obstructing and absorbing the heat raysas do the circular strips herein shown.

It has been found in practice that if the I walls of the conduit are hotter than the fluid, heat will be radiated from the walls of the conduit to the fluid. Under these circumstances, heat energy will be radiated toward the outer side of the thermometer resistance 4:, and toward the outer side of the thermometer resistance 3 from the walls of the conduit. Heat rays may therefore be di-' rected on the unprotected side of the thermometer resistance .3, and on the unprotected side of the thermometer resistance 4: from the walls of the conduit. the walls of the conduit, in advance of the thermometer resistance 3, mayradiate heat energy toward the under side of the thermometer resistance 3, and the walls of the conduit beyond the thermometer resistance 4 may radiate heat energy toward the upper side of this thermometer resistance.

In order to protect the thermometer resistances' from heat rays emanating from such sources as just described, an additional ray screen 18 is associated with the thermometer resistance 4 at the side which is opposite to the side at which the screen 14 is located. Likewise, an additional ray screen 19 is associated with the thermometer resistance 3 at the side which is opposite to the side at which the corresponding screen 14 is located.

. In Fig. 1 these additional screens areas-- sociated with the tubular frames which carry the thermometer resistances in, the same manner that the ray screens 1 1 are associated therewithr' In Fig. 2 the additional ray screens constitute separate units just as the other ray screens constitute separate units in this figure.

The additional ray screens obstruct and absorb the rays directed toward the upper side of the thermometer resistance 4:, and directed toward the lower side of the thermometer resistance 3 in the same manner that the ray screens 1 1 intercept and absorb the rays directed toward the inner side of the thermometer resistances.

In other words,

, been provided in which errors due to radiant energy effects from practically any source whatsoever are eliminated.

What I claim is:

..1. A fluid meter comprising a conduit, a heater and a: temperature responsive element located in said conduit, and means to protect the teu'lperature responsive element from radiant energy directed toward either side of the temperature responsive element;

2. A fluid meter comprising a conduit, a

, heater and a temperature.responsive element located in said conduit, and means to prevent the temperature responsive element from being affected directly by radiant energy from sources at either side of said element.

3. A fluid meter comprising a conduit, a heater and a temperature responsive element located therein, means to protect that side of the temperature responsive element which is adjacent to the heater from the radiant energy from the heater, and means to protect the other side of said element from radiant energy from the walls of the conduit.

4. A fluid meter comprising a conduit, a

heater and a temperature responsive element located therein, and a ray screen located at each side of said temperature responsive ele ment for obstructing and absorbing radiant energy before it reaches said element, said screens offering no material obstruction to the flow of the fluid.

A fluid meter comprising a conduit, a temperatureresponsive clement located therein and ray screens located on opposite sides of said element to protect the same from radiant energy directed toward either side thereof, each of said screens comprising a plurality of relatively thin strips disposed in said conduit with their surfaces of maximum area substantially parallel to the direction of flow of fluid throughsaidconduit.

6. A fluid meter comprising a conduit, atemperature responsive element located therein and ray'screens located on .opposite sides of said element to protect the same from radiant energy directed toward either side thereof, each of said screens comprising a plurality of concentrically arranged rings formed of relatively thin material and dis- 'pesed in said c ondnit with their surfaces-0f @maximurn area substantially parallel to the directien of flow of fluid through said conduit. a 5 I 7 The method of preventing a tempera- .ture responsive elem en't located in a stream of fluid being affected directly by rays from HORACE N. PACKARD. 

